Bus bar housing



May 10, 1949. w. M. sco'rT, JR 2,469,445

BUS BAR HOUS ING 8 Sheets-Sheet 1 Filed March 25, 1944 IN V EN TOR.

W/ZL/lI/W/W JTVU'JR May 10, 1949.

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BUS BAR HOUSING 8 Sheets-Sheet 3 Filed March 25, 1944 75 a MW 46 mi KIMMay 10, 1949. w. SCOTT, JR 2,469,445

BUS BAR nousme Filed March 25, .1944 8 Sheets-Sheet 4 lav/M May 10,1949.

W. M. SCOTT, JR

BUS BAR HOUSING 8 Sheets-Sheet 5 Filed March 25, 1944 NA b May 10, 1949.w. M. sco'r'r, JR

BUS BAR HOUSING 8 Sheets-Sheet 6 Filed March 25, 1944 [N VEN TOR.

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BUS BAR HOUSING May 10, 1949.

8 Sheets-Sheet 8 Filed March 25. 1944 mmvron M1 mm m. JCOU JR PatentedMay 10, 1949 UNITED STATES PATENT OFFICE BUS BAR HOUSING William M.Scott, Jr., Bryn Mawr, Pa, asslgnor to I. T. E. Circuit Breaker Company,Philadelphia, Pa., a corporation of Pennsylvania Application March 25,1944, Serial No. 528,051

8 Claims.

1 My present invention which is a continuation in-part of applicationSerial No. 462,237, filed October 16, 1942 now Patent No. 2,396,13l,issued March 5, 1946, relates to bus bar supporting members andhousings, and more particularly to a means for providing a continuoushousing for a bus bar whereby the bus bar is supported in appropriaterelation to other elements of the system and is fully protected.

My invention is primarily directed to a continuous housing for a bus barformed essentially of continuous tubes which in one form may be ofinsulating material supported between spaced structural metallicmembers. The said structural metallic members are designed with minimumclearance to the conductors so that the continuous housing is protected.

My invention further contemplates the arrangement of the housing supportfor the bus bar so that a weather-proof continuous housing is providedtherefor; while, nevertheless, access may readily be obtained to theinterior of the housing to enable removability, cleaning, inspection, orreplacement of insulators or other elements after assembly, withoutinterfering with the housing or the bus covering.

Indeed, my invention contemplates the formation of the continuousweather-proof housin in such a manner that inspection may even bepossible while power is on.

Heretofore, it has been thought necessary in building circular housingsfor bus conductors to construct each section of the housing of twomatching half-cylindrical members which are then secured together in anyappropriate manner.

My invention, by making it possible to utilize continuous tubularmembers as the housing for the bus conductor, makes it thereby possibleto obtain a stronger housing, better able to withstand external blows orelectrical stresses, and even internal pressure due to gases formed onshort circuits.

Myinvention also contemplates the utilization of removable means inconnection with the structural members which support and space thecontinuous housing members to permit ventilation and accessto theinterior of the housing at any time. d

Inone embodiment of my invention, I utilize non-metallic tubular membersbetween the structural supporting members of my housing, in which 2 inits cheapness, availability, and lightness for strength.

Since it is desired that any flash-over from the 7 bus conductor to thehousing be conducted imcasethe necessity for: insulation at each'of thestructural members is obviated. The non-metallic'housing, which may heof asbestos or any other electrically insulating material, isadvantageous mediately to the metallic supporting rin or otherstructure, the said metallic ring member is provided with ribs whichproject inwardly for substantial distances to ensure that the flash-overis to the metallic ring.

In order further to ensure conduction to the metallic ring and otherstructural support, the

, insulating tube forming the housing may be provided with a metalcoating on its interior, which coating is grounded to the supportingring to ensure the grounding of any flash-over. Such a metallic coatingmay, in appropriate cases, be also placed on the outside of theinsulating tube or on both sides of the insulating tubes; or may even beincorporated and embedded in the material of the tube itself.

To facilitate manufacture and assembly, the structural metallic rings,which furnish the support and spacing members for the continuous tubes,may each be made in two half-sections which are bolted together; and, inappropriate cases, one-half of the ring may be made of magnetic materialand the other half of non-magnetic material.

Accordingly, the primary object of my invention, as expressed in theforegoing, is the formation of a novel continuous housing for a busconductor.

Another and corollary object is the formation 0 such a novel continuoushousing from a continuous member or tube of insulating material.

Still another object of my invention is the arrangement of thecontinuous housing in such a manner that an appropriate path is providedfor any fiash-over to ground so that the housing, as well as the busconductor, is protected.

These and many other objects of my invention will become apparent in thefollowing description and drawings in which:

Figure 1 is a view in perspective of a threephase bus run built inaccordance with my invention. 1

. Figure 2 is a fragmentary view in perspective showing a structuralringof a slightly modified form which supports and spaces the bus conductorand likewise supports and spaces the contlnu-- ous tubular housing. Thebus conductor here 3 4-4 of Figure 3 looking in the direction of thearrows showing the relationship between a circular bus conductor and thesupporting rings.

Figure 5 is a top view of one of the supporting rings taken from line 55of Figure 4 looking in the direction of the arrows.

Figure 6 is a cross-sectional view of the supporting ring taken fromline 6-5 of Figure 4 looking in the direction of the arrows.

Figure 7 is a cross-sectional view corresponding somewhat to thecross-sectional view of Figure 6 showing, however, the formation of aring within which two bus conductors are joined end "to end.

Figure 8 is a fragmentary enlarged view of the righthand portion ofFigure 4 showing the method by which the cover member for the hand-holesin the supporting ring is secured in position.

Figure 9 is a side view of a slightly modified form of supporting ringfor the continuous hous- 121:.

Figure 10 is an end view of the ring of Figure 9.

Figure 11 is a fragmentary view in perspective of a preferred form ofsaddle for supporting the bus conductor, the said saddle of course beingsecured to the end of an insulator.

Figure 12 is a fragmentary view of a corner joint for the housing ofFigure 1.

Figure 13 is a fragmentary cross-sectional view taken on the line l3--l3of Figure 12, looking in the direction of the arrows, showin the mannerin which a single supporting ring member may be utilized withoutmodification to support housings of different thicknesses on oppositesides,

Figure 14 is a fragmentary cross-sectional view taken on line "-44 ofFig. 12 looking in the direction of the arrows showing a modifiedarrangement for a ring whereby the opposite sides of the ring havedifferent formations to facilitate the support of different sizes andthicknesses of housings and to position the housings in different Ways.

Figure 15 is a fragmentary cross-sectional view of the wall of thecontinuous insulating housing member showing a metallic mesh embeddedtherein.

Figure 16 is a fragmentary view of the wall of the continuous insulatinghousing member showing a metallic coating on the interior of thehousing.

Figure 17 is a fragmentary view of the wall of the continuous insulatinghousing member showing a metallic coating on both sides of the housing.Figure 18 is a cross-sectional view corresponding substantially to thecross-sectional view of Figure 4 but showing a modified form ofinsulator support for the bus conductor within the housing.

Figure 19 is an enlarged cross-sectional view of the insulator supportof Figure 18.

Referring now to Figure 1, I have here shown a three-phase bus systemcomprising the bus conductors 20 each supported within its owncontinuous housing 2|, 2!. The housings are supported from any suitablestructural members which, in this case, are shown to be a plurality ofI-beams 22, 22, which, in turn, are supported on risers 23, 23.

A metallic supporting ring, 25, preferably of cast bronze, is secured tothe I-beam 22 in any suitable manner, preferably by bolts passingthrough the base 26 of the supporting leg 21 of the metallic supportingmember and into the flanges of the I-beams 22.

The supporting rings 25 are spaced apart by distances which aredetermined by the length of the tubular continuous housings ill ofinsulating material .which are supported between spaced rings 25.

Accordingly, the I-beams 22 and the supporting structure for the said-I-beams are likewise spaced in accordance with the predetermineddimensions of the insulating tubular housings 30.

As will be obvious from Figure l, the arrangement of the supportingrings 25 and the structural members which support the same are such asto permit appropriate and necessary changes in direction and taps fromthe bus.

As has been above pointed out, the'contlnuous housing member 30 is acontinuous tube of insulating material, preferably of asbestos which isfire-resistant.

Each link of continuous tubular housing 30, is, as above pointed out,supported between a pair of opposite rings 25. The form of thesupporting ring itself may more readily be seen in the side view ofFigure 3 and the cross-sectional view of Figure 4 as well as in views ofFigures 5 and 6, which figures should be considered together.

The structural ring 25, as shown in these flgures, comprises anupper-half section 32 and a lower-half section 33. These half-sections32 and 33 are formed of metallic castings (preferably bronze) which arebolted together in any appropriate manner. The preferred means forbolting these half-sections together is a centrally disposed lug orledge 35, 35 (see Figures 4 and 5) at the end of each half-sectioninterposed between the ribs 40.

The lugs or ledges 35 match with each other, as shown in Figure 4, and abolt 38 may be passed through the matching openings 31 to secure thehalf-sections32 and 33 together.

Where desired, and where the electrical characteristics of the supportmake it useful, one of the half-sections of the supporting structuralmember 35 may be made of magnetic material and the other half-section ofbronze or other similar substantially non-magnetic material, for reasonsexplained hereafter.

Asseen in Figures 4 and 6, each of the structural metallic supportingmembers 25 is pro vided with a pair of spaced, parallel, inwardlyextending annular supporting ribs 40, 40 for purposes hereinafter morespecifically set forth.

As is also seen in Figure 5, at least the upper half section 32 is outout to provide hand-holes 42, 42 to afford ready access to the interiorof the housing even after the same has been completely assembled.

Likewise, as is seen in Figures 4, 5, and 6, the upper central sectionof the half-section 32 of housing 25 has a. solid continuous section 44interconnecting the opposite sides of the half-section 32 and providinga supporting means for the insulator 45. The lower half-section 33 isalso provided with heavier connecting portions 41 between the ribs, inorder also to provide for appropriate support of, the lower insulators45', 45.

It will be obvious. of course, that the upper half section 32 may bearranged so that two insulators 45 are spaced from each other, and thelower insulators 45 may also be spaced 90 from each other to provide forthe utilization of four insulator supports rather than three as hereshown. The number of supports which will be used is, of course,dependent on the particular structural and electrical conditions to beencountered.

In the ordinary case where the bus run is horizontal, it may besufficient toprovide for two lower insulator supports 45' and but oneupper spacing and supporting insulator 45. Where the bus run isvertical, or under other special conditions, it may be desirable to havefour equally spaced insulators in order to provide for appropriatesupport.

The insulators 4.5 and 45 are preferably supported in the structuralmember 25 in the manner described in my Patent No. 2,396,131. That is.each of the elements 44 and 41 is provided with a threaded opening 50into which an insulator supporting stud having a threaded end 52, may bethreaded. The threaded end of the stud 5| is provided with a hexagonalbore 53 to facilitate screwing the same into the opening 50.

After the stud 5| is in position, lock washer 54, having a hexagonalopening, is screwed into the opening 50, and a lock nut 55, having asimilar hexagonal bore, is screwed into the opening 50 thereby pullingthe lock washer 54 up tight against the end of the stud 5| and thuslocking the stud 5| in the selected position.

The stud 5| is slightly frustrum-conical in shape and has an end 56which is a section of a sphere The end 56 bears against thecorrespondingly shaped inner surface 51 in a metallic socket 58 embeddedin the insulator 45 or 45.

The section 60 of the stud 5| adjacent the open end of the socket 58 isrounded so that the stud 5| in the socket 5B, and hence the insulator 45or 45', may have relative movement with respect to each other.

The saddle 62 at the opposite end of the insulator which engages the busconductor 20 is preferably transversely arced, as described in myabove-mentioned patent, in order to provide for a line contact betweenthe said saddle and the bus conductor 20 to permit the insulator 45 or45' to tip slightly in accordance with any movement of the bus conductor20 with respect to the structural supporting member 25. This, too,follows the principles specifically described as set forth in my abovementioned application.

As shown in Figure 11, the preferred form of saddle 62 is that which hasa shank 64 embedded in the end of the insulator in any suitable man-.

ner and abus supportin portion 65 which is curved to engage the busconductor 20, but which is transversely arced on its supporting surfaceso that the saddle engages the bus conductor 20 only over a singletangential line. The saddle and hence the insulator may therefore rockwith respect to the bus conductor 20, as bus 20 undergoes a slightmovement owing to electrical or thermal stresses.

All of these principles involving the rockin of the insulator 45 withrespect to the support for the said insulator and with respect to thebus conductor have been specifically described in my aforesaid PatentNo. 2,396,131 and reference is made to said application for elaborationof the said principles.

By permitting this rocking movement to occur, uneven stresses on theceramic of the insulator are avoided as shown in my aforesaid patent:the rocking of the insulator does not diminish the support since thetransversely arcuate portion of the saddle is curved on an are having acenter at the pivot of the insulator, and the pivoting members aremetallic inserts in theceramic of the insulator.

As shown more specifically in Figure 6, each of the supporting rings 25has a lateral annular porting structure or I-beams 22.

The lower insulating supports 45', 45 are supported by their respectivestuds which, in turn, are supported in the respective tapped openings50. The bus conductor 20 is then laid down on the lower insulators 45and rests thereon. The continuous tubular hous ngs 30 are then laid inposition between the lower halves 33 of the structural supportingmembers 25 so that the ends thereof rest on the lower annular flanges 10of the lower half section 33.

When the continuous tubular insulatin housings 30 are appropriatelyplaced in position, then the upper half section 32 is placed in positionover the ends of the tubular housings 30 and over the lower half-section33. The upper surfaces of the ends of the housings 30 are receivedwithin the annular flange extension 10' of the upper half section 32.The upper half sections 32 are then bolted to the lower half sections 33by means of the bolts 36, as previously described,

' through the handholes 42 in the upper half section 32; and theninsulator 45 is placed in posi tion and is appropriately adjusted on itsstud so that it furnishes a spacing and support between the upperportion of the structural ring 25 and the bus conductor 20.

The bus conductor 20 is inspected through the hand-holes 42 andappropriate adjustments of all of the studs 5| of all of the insulators45 and 45' are made until the bus conductor 20 is appropriatelypositioned by the insulators 45 and 45.

Now, the only openings leading to the interior of the housing are thehand-holes 42. These hand-holes may now be closed by a flexibl stripwhich covers the same. The flexible metallic strip is indicated at '15in Figures 3, 4 and 6.

The flexible metallic strip 15 is secured by means of the studs 15a tothe external portion of the lug 35 at the left-hand side of the lowerhalf section 33 of the structural member 25 (see Figure 4). Although (asshown in Figure 5), only one such bolt 15a is shown, any appropriatenumber of such bolts may be used in order to obtain proper securement.

The upper half section 32 of the structural supporting member 25 isprovided with a pair of opposite spaced ledges 16, IS in order tosupport the flexible metallic band15.

The flexible metallic band is of a sufficient length to wrap around thewhole of the upper section 32 and is secured on theright-hand side bymeans of the clamping units 18. The flexible metallic band 15 thuscovers the hand-holes 42,

The clamping units 18 each consists of a bolt 19 pivotally connected bymeans of the pin 80 to a lug 8| extending outwardly from the upperright-hand side (Fig. 4) of the lower half section 33 of the supportingring 25. The bolt 19 has an adjustable clamping nut 82 threaded thereon.It is also drilled with a hole 85 to receive a lock, thus preventingunauthorized persons from removing the metallic band.

An angle bracket 83 is secured in any suitable manner, as for instanceby welding or brazing, to the free end of the flexible covering strip15. The said angle bracket 83 has a plurality of open ended slots 84 inthe unsecured leg thereof into each of which a bolt 19 may be swung, asshown in Figure 8.

When the bolt 19 has been rotated upwardly and swung into theappropriate slot of the angle bracket 83, the clamping nut 82 may betightened down on the bolt 19 to draw the flexible metallic coveringstrip down tight. A suflicient number of clamping units 18 should beused to ensure proper and even closing tension on the flexible metallicstrip 15. In appropriate cases, and where it is necessary, the lowerhalf section 33 may be provided withventilating holes on the undersidethereof. However, in order to prevent direct entry of foreign materialinto these ventilating holes, a lower covering band 90 (Figures 4 and 6)may be secured by means of bolts between the ledges SI, SI on oppositelegs 21 and by means of bolts 92 passing through the covering strip 90into the ledges 9i.

Additional bolts 93 may also be passed through the center of the lowercovering strip 90 into the lowest portion of the lower half section 33of the supporting ring 25. By this means, a slight tor tuous path isprovided for the entry of the air into any ventilating hole which may beprovided in the lower half section 33: that is, the air Will first enterlaterally into the spaces 95 (Figure 4) and then vertically into theinterior of the housing.

In Figure 7, I have shown partly in cross-section the kind of supportingring which may preferably be used where a joint or connection be tweentwo adjacent bus runs is to be made. In this case, the ring 25' (Figure7) has all of the structural and other characteristics of the supportingring 25 of Figures 4, 5 and 6, except that it is double in width and isprovided with two spaced sets of tapped openings 50 in the supportingportions 44' for positioning and adjusting the two sets of insulators45".

In this case, the buses 20' are for purpose of illustration shown assquare buses, and the insulators 45" have exactly the structuredescribed in my Patent No. 2,396,131 above referred to.

An expansion joint connection between the two adjacent bus runs 20' isprovided by the flexible conductors I which are secured in any suitablemanner, as for instance, by the bolts IOI, to the adjacent ends of thebuses 20'. The spacing of the ends of the bus conductors 20 permitsappropriate expansion and contraction or other movement of the buseswith respect to each other, pursuant to electrical and thermal stresses.As pointed out in the above-mentioned Patent No. 2,396,131, the centerof each bus run is preferably the portion thereof which is anchored sothat the full expansion of the bus from the center out to either endwill result in a smaller expansion than if one end were anchored.Consequently, the free ends of the buses have relative movement withrespect to the supporting structure and the adjacent ends of theadjacent buses. The flexible connection I00 and the double supportingstructure, by means of the two sets of insulators 45" in the widenedsupporting ring 25', permit this action to occur.

Except for the parts above more specifically described, all of the otherparts of the supporting ring 25' correspond to the similar parts of thesupporting ring 25 of Figures 4, and 6, and the same reference numbershave been applied thereto.

As shown in Figure 16, the interior of the insulating tube 30 may have ametallic lamination II 0 secured thereto in any suitable fashion, as,for instance, by spraying a finely divided metal with a suitable binderthereon in suflicient thickness to render the said coating IIII fullyconductive.

As shown in Figures 16 and 6, such an interior coating IIO will serve toconduct any possible short circuits which fail to flash over to the rib40 of the supporting metallic structure 25.

A pigtail connection I I2 may be secured in any suitable manner, as, forinstance, by brazing, between the inner metallic coating IIO and the rib40 in order to ensure a complete by-pass of any short circuit orflash-over which may extend from the bus to the inner coating I I I].

In appropriate cases, and where it may be desired, in order to procurethe best results, not only may an inner metallic coating I Ill be used,but, as seen in Figure 17, an outer metallic coating II5 may also beapplied to the surface of the insulating housing 30.

Inappropriate cases, where it may be desired not only for electricalpurposes but also for additional structural support, a metallic mesh orother similar substantially continuous metallic layer II6 (Figure 15)may be embedded in the tubular insulating housing 30.

It is, of course, clear, as above pointed out, that Whenever suchmetallic linings or laminations are used, they must be grounded by asuitable connection to the metallic ring 25. As above pointed out,one-half of the supporting ring may be of magnetic material and theother half of nonmagnetic material.

In Figures 2, 9, and 10 I have shown a modified 0 form of metallic ringsupport I25 for the bus I20.

The bus is here shown as a square bus; although this same type ofmetallic ring support I25 may be utilized in connection with any otherkind of bus.

The structural supporting ring I25 of Figures 2, 9 and 10 is providedwith inner annular ribs I for purposes previously described, and withoutwardly extending flanges I10 and I10 which correspond respectively tothe flanges 10 and 10 of the supporting ring of Figures 4, 5 and 6.These annular outwardly extending flanges I10 and I70 are provided withan annular groove HI I to receive the gasket I12 to form a weather-tightseal between the supporting ring I25 and the continuous housing I30.

The opposite flanges and rib rings I40-I10 are interconnected at spacedintervals by the support ing members I44, which are each provided withthe tapped openings I50 to receive the appropriate stud which willsupport the insulator I so that it will properly position the bus I20.The insulator I45 in this case has the same structure and operation asthat described in connection with my aforesaid Patent No. 2,396,131.

The upper half I32 of the composite ring I25 is secured to the lowerhalf I33 of the composite ring I 25 by means of bolts I35 passingthrough the corresponding abutments or ledges I35.

The legs I21 are secured in any suitable manner to the outside surfacesof the annular flanges I10 as, for instance, by bolts I21.

Complete hand-holes I42, I42 are provided. as seen in Figure 9, andFigur 2 in both the upper hall I32 and the lower half I33 of thestructural supporting ring I25.

A fully encircling flexible metallic strip I15 is supported on theledges I16.. This flexible metallic strip I15 (in contrast to theflexible metallic strip 15) fully encircles the whole ring.

Clamping units I18, similar to the clamping units 18 shown in Figure 8,are used to tie together opposite ends of the flexible metallic coveringband I15.

.In this case, however, the angle brackets I83 (which correspond to theangle brackets 83 of Figure 8) are secured to one end of the band; andthe opposite bolts and nuts supported by the lug II are secured to theother end of the band. By this. means, therefore, all of the hand-holesI42 are fully closed up after the structure is assembled.

The annular ledges I16 may be provided with a corresponding annulargroove I16a to receive an appropriate gasket to form a weather-tightseal.

In all other respects, the structural supporting ring I25 of Figures 2,9 and 10 corresponds to the structural supporting ring 25 of Figures 4,5 and 6.

The assembly of the units, including the structural supporting ring I25,is the same as that with respect to the units including thestructuralsupporting ring 25. That is, the lower half I33 is secured in positiononthe supporting framework, the bus is mounted in position, the insulatingtube I3Ilis mounted in position in the manner described for tube 30 ofFigure 4, the upper half I32 of the structural supporting ring I25 issecured in position, appropriate adjustments are made through thehand-holes I42, and the flexible metallic strip or band I is thensecured.

Once the flexible metallic strip or band I15 is in position as'anall-over cover and located in place, the insulators cannot be moved oradjusted, and there is no access to any part.

Inappropriate cases, the flexible metallic strips or hands I15 may beprovided with perforations for ventilation; and, since the bands may bemoved with respect to the ring and placed thereon with the lockingmembers I18 in any position, the ventilating perforations in the bandI15 may be positionedwherever desired to permit ventilation and preventundue exposure.

Referring now to Figure 12, I have here shown an enlarged view of thecorner piece 200 of the bus housing of Figure 1.

The corner piece 200 consists of four metal sections 2M, 21H and 2M.SectionsZIJI lie directly beneath sections MI.

The abutting end of the sections 2M, 2M and 2M, 2M are cut at a 45 angleso that they may abut each other along the seam 202. The seam 202 isclosed in any suitable manner in order to preserve the weather-proofnessand continuity of the entire housing. The sections are thus formed intoan upper and lower half and fastened together by bolts 205.

The supporting rings 225, 225 on each side of the corner piece 200correspond to the supporting rings 25 of Figures 4, 5 and 6 in everyrespect, with the sole exception that the annular flanges 210 (seeFigure 14) and 210a have different shapes. The annular flange 21011which is to receive the end of the continuous tube 30, as shown inFigure 14, corresponds to the annular flange 10 of Figure 6 and isprovided with an annular groove 21Ia and annular gasket 212a, which areslightly wider than annular groove 1| and annular gasket 12.

An annular groove 21I is provided on the outside surface of theannular'flange 210, and a gasket 212 is positioned in thesaid groove onthe outside surface of the annular flange 210 to bear against the end ofthe section 2M. The end or tube 2IlI thus surrounds the annular flange210.

Some of the shapes as for instance elbows and Tscannot be made ininsulating materials as they can in metals (Figs. 12 and 13 are shown toindicate one of the supporting structures adapted for insulatingmaterial on one side and a metal enclosure on the other side).

In Figure 13 I have shown a modified method of receiving and supportingthe corner piece which utilizes a supporting ring 32 5, which is inevery respect similar to the ring 25 of Figures 4, 5 and 6,

,' except that the annular grooves 31I in the annular flanges 310 arewider and receive a wider gasket 312.

'The ring of Figure 13 differs from the ring of Figure 14, flrst, byreason of the fact that opposite sides of the ring 325 of Figure 13 arethe same, and second, by reason of the fact that the end of tube 2Ill ofthe corner piece 200 is received on an extension piece 3Ill, fitting theinterior of the flange 310.

In Figure 13, the ring 325 is so arranged, however, that the flange 310on one side, which will properly receive the end of the tube 30, willdefine a circle slightlysmaller than the outside diameter of the cornerpiece 200 on the other side. Therefore, as seen in the right-hand sideof Figure 13, an insert sleeve 3M is provided having an outside diameterwhich will just fit inside the flange 310 and be made weather-tight bythe gasket 312 and which will fit just inside the corner piece 200which, in this case, extends up to the outside lateral edge of theflange 310.

The extension tube 3IlI is preferably secured into the corner-piece 200,as shown in Figure 13, in such manner that a weather-tight seal isformed between the corner-piece 200 and the in;- sert sleeve 3IlI.

In Figures 18 and 19, I have shown a structural supporting ring 25corresponding exactly in every respect to the structural supporting ring25 of Figures 4, 5 and 6, but I have here shown a supporting insulator445 of modified form. In Fig. 4,

as well as in the other figures thus far described in connection withthose figures, the insulator pivots around a stud 5| carried by thehousing and is provided with a saddle for supporting the bus wherein thesaddle has a transversely arcuate section. Thus, the insulator may pivotwith respect to its support on the ring 25 and rock on the arcuatesaddle surface with respect to the bus.

In Figures 18 and 19, the reverse operation is shown wherein theinsulator pivots around a stud secured to the bus and rocks on anarcuate surface with respect to a supporting member on the structuralsupporting ring 25.

Thus, as shown in Figures 18 and 19, a stud 45I is provided with asaddle 452 which is secured in any suitable manner as for instance, bybolts 452a to the bus 20. The stud 45I is thus absolutely stationarywith respect to the bus 20. v

The insulator 445 is provided with a metallic insert 458 having a base451 which is a section of a sphere. The end of the conical stud 45I alsohas a surface 456 which is a section of a sphere.

A washer 456a is provided between the end 456 of the stud and thesurface 451 of the socket 458.

The stud 45I is provided with rounded shoulders 460 so that the socket458, and hence the entire insulator 445, may rock against the stud 45LThus, the action of the insulator 445 around 11 the stud 4H of Figures18 and 19 is exactly the same as that of the insulator 45' of Figure 4about its stud 5i, and the rocking action is also that described inconnection with similar members in my above-mentioned Patent No.2,396,131.

The end of the insulator 445 opposite the bus is provided with ametallic extension "I secured by cement or other suitable material 402in the end 403 of the said insulator 445.

A metallic extension 401 of the insulator 445 is provided at its endwith a head 405 having a surface 405 which is part of a sphere.

The spherical surface 406 has a radius extending from the (imaginary)pivot point 401 of the insulator 445 as a whole: that is, when theinsulator rocks about the stud 45!, the pivot is approximately at thepoint 401, and in order to obtain a point contact between the sphericalhead 405 and the substantially flat surface on the end of the stud 4| I,which is secured to the supporting ring 25, the spherical surface 406 isformed on the center 401. Similarly, in order to ensure appropriaterocking action of the insulator 445. the spherical surfaces 455 and 451have the point 401 as a center.

The stud 4 is secured in the tapped opening 50 of the supporting ring 25by a threaded run from the interior. when it is appropriatelypositioned, it is locked in position by the washer 454 and the lock nut455. The stud 4 is ad- Justed inwardly so that when the insulator 445 isperpendicular to the bus 20 and the surface 0, a tight fit is obtained.

Since the insulator 445 as a whole rocks about the point 401, and theradius from the point 401 to the surface 406 is always the same, thesame tight adjustment will be maintained between the surface 0 and thehead 405 of stud 40i irrespective of the angular position which theinsulator 445 may assume with respect to the head 0 of stud 4H and withrespect to the access of the bus 20.

Thus, should the bus expand or contract or have other movement due toelectrical or thermal stresses, the ceramic portion of the insulator 445will not be sheared or cracked by this movement, but the insulator 445may rook freely with respect to the bus 20 and the opposite support topermit Cal automatic adjustment of the position of the bus 20. For thispurpose, therefore, the principles previously described in my Patent No.2,396,131 are followed.

The difference between the present structure described in Figures 18 and19 and those described in the aforesaid application is that theinsulator rocks about a pivot which is secured to the bus, rather than apivot which is secured to the supporting structure, and has a tangentialor point contact with a portion of the supporting structure rather thanwith a portion of the bus. Otherwise, the underlying principles arestill the same.

I have found that, for proper operation, the surface 4| 0 of thestationary stud 4 may be perfectly flat.

There should be a high coeiilcient of friction between surfaces 405 and0 to ensure that surface 406 will rock with respect to surface 0 and notslide with respect thereto. For this purpose, either of the surfaces maybe roughened slightly.

My invention enables the removal, cleaning, inspection, or replacementof the insulators through the hand-holes after assembly and withoutinterfering with the housing or bus covering. Such operations involveonly the removal of a relatively slight cover over a portion of thestructural member itself.

' The housing is made as a continuous tube rather than in sections;thus-making the housing stronger than a housing constructed of partcylindrical members as was done in the prior art. The housing may thusbetter withstand external blows or electrical stresses or internalpressures due to gases formed on short circuits. The continuous housingalso lends itself readily to outside construction because it isweather-tight; the utilization of appropriate gaskets over thehand-holes will ensure a complete weather-tight construction.

Inspection of the bus structure and insulators is possible while poweris on, because only relatively small cover pieces over the structuralsupporting member need be removed for such inspection.

The supporting rings or structural members an'e provided with ribs whichensure minimum clearance between structural members and the busconductors, so that any flash-over which is formed may be to themetallic structural ring which is grounded,

Since the asbestos material to the tubular housing member issemi-conductive, any flash-over to the said tubular member may bereadily conducted to the metallic structural member and grounded. Asabove pointed out, in order to ensure such conduction of any flash-overto the tubular member to the metallic supporting structure, metalliciaminations may be applied as a surfacing material to the interiorsurface of the asbestos tubular member. In appropriate cases, theoutside surface may be also laminated with metal and, as above pointedout, in appropriate cases, a metallic mesh or other material may beincorporated within the housing itself. The metal, as above pointed out,may be sprayed on with a suitable binder to hold the same in place. Ihave found that an asbestos metallic coating sufliciently serves thepurpose.

Since the housing 30 itself is essentially nonmetallic, the necessityfor insulation at I each structural supporting ring is obviated.

The non-metallic housing formed of asbestos or other suitable materialis advantageous in its cheapness, its commercial availability, andlightness of weight. Further, since asbestos is fireresistant, a realhazard in bus structures is'eliminated.

The metallic supporting structures herein described may be utilized asreadily with three or four insulators or any other suitable number whichmay be required in any appropriate case.

Appropriate ventilation may be provided by the utilization of protectedopenings in the structural supporting members. Ventilating openings maybe provided either in the lower half section of the structuralsupporting member with an appropriate cover or baflie over the openingsto provide a tortuous path for the air; or perforations may be providedin the covering band of the structure shown in Figures 2, 9 and 10, andthe covering band may be turned to a position where the openings orperforations are protected. Once the covering band is in place andlocated, the insulators cannot be moved or adjusted, and there is noaccess to any part.

Since the structural supporting rings are in half-sections, one half ofthe ring may be made of magnetic material and the other hall ofnonmagnetic material.

Under normal conditions with current flowing in the bus bar it issurrounded by a magnetic field. Any iron which is present in thismagnetic field will have magnetic lines of force set up in it which inturn induce eddy currents and they in turn heat the iron and increaseits temperature. This is particularly true if themagnetic materialsurrounds the bus bar so as to form a continuous pathfor the magneticfield surrounding the bus. When the supporting structure is made withboth halves of magnetic material this forms a complete path for themagnetic field and magnetic fluxcirculates in it. With current in thebus of say ,800 amperes, this heating is not great enough to exceedcommercial limit. If, however, the current in the bus should increase tosay 1200 amperes, this heating would become excessive.

In order to avoid overheating, the supporting frame is made withone-half non-magnetic material which breaks up the circular path andlimits the flux to a point where even the remaining hall? which is madeof magnetic material does not overheat. In addition, if the bus iscarrying a much higher current such as 4000 amperes, it may be thatfield intensity is so great that any magnet would overheat and it isnecessary to make the whole ring of non-magnetic material. Thus it willbe seen that when the supporting frame is made in two halves quite avariety of conditions can be met without overheating and at the same,time using the least expensive material.

In the above, I have described my tubular structure as made ofinsulation material. In another embodiment of the invention, I employ ametallic tubular structure. Where the tubular enclosing member is madeof metal which is magnetic, this heating phenomenon also appears in it.Rolled material heats very much more than a cast material in the rangeof currents usually applied with this bus construction. In such cases, Iemploy brass or copper.

There are also currents induced in this tube when made of metal, whichrun lengthwise in the tube similar to the sheath currents in a lead-.covered cable. When the enclosing tube is made of metal or is made ofinsulating material such as asbestos and has provided either an insideor outside metal coating, it is desirable to'ground this coating only atone end and to leave a, small gap between the coating and the'supporting r frame at the other end so as to provide no circuit forthese currents.

The use of an enclosed bus of this kind very largely eliminates anypossibility of a flash from the busto ground. This is because the typeconstruction eliminates dirt, keeps out animals and even if ionized gaswere present due to an adja cent fault the tight enclosure protects theinsulating value of the air within the enclosure and faults of this kindare avoided. It might happen, however, that the high voltage surgescaused by switching or by lightning might increase the voltage of thebus to the point where the insulation through the air would break down.Should this occur, provisions are made in the design to quickly conductthis flash over to ground at points where the minimum destruction wouldoccur. To this end the supporting casing has ribs that stand out higherthan the rest of the grounded material so as to form the arcing pointand to quickly cause a'iiash to ground which would excite the circuitbreakers on the line which Will open and clear the fault with a minimumof destructions.

For safety of operators and anyone who might come in contact with thebus run, the supporting in the art.

14 frame is connected by a. copper ground bus to the station ground. Ifthe continuous tube, surrounding the bus, is made of metal, it tooshould be grounded at one end leaving a gap at the other end so thatcirculating currents will not occur. If, however, the continuous tubeismade of insulating material either on the inside or on the outside, itmay be coated with metal and that metal grounded at one end to provideground potential wherever the tubing might be touched on the outside,otherwise a high resistance to ground might result in a potentialgradient, a high enough potential to shock anyone who came in contactwith it.

In the foregoing I have described my invention only in connection withpreferred embodiments and preferred uses and applications thereof.

Many other embodiments and applications of my invention should now beobvious to those skilled Accordingly I prefer to be bound not by thespecific disclosures herein but only by the appended claims.

I claim:

1. A bus bar housing comprising a bus bar en- I closure; a supportingframe therefor; said frame including means for supporting said bus barenclosure and means for supporting a bus bar along the axis of saidenclosure; said last mentioned means comprising a plurality of insulatorsupporting members on said frame; insulators supported thereby, each ofsaid insulators engaging said bus bar and spacing it from the frame;each having a universally pivotal mounting at the end engaging the busbar and an arcuately shaped member at the other end curved on an archaving the pivoting point of said universally pivotal mounting as acenter; a member having a substantially plane surface carried by saidframe; said surface being directed toward said bus bar and arrangedsubstantially normal to said insulater, the curved surface of saidarcuately shaped member bearing against said plane surface.

2. A bus bar housing comprising a bus bar enclosure; a supporting frametherefor; said frame including means for supporting said bus barenclosure and means for supporting a bus bar along the axis of saidenclosure; said last mentioned means comprising a plurality of insulatorsupporting members on said frame; insulators supported thereby, each ofsaid insulators engaging said bus bar and spacing it from the frame;each having a universally pivotal mounting at the end engaging the busbar and an arcuately shaped member at the other end curved on an archaving the pivoting point of said universally pivotal mounting as acenter; a member having a substantially plane surface carried by saidframe; said surface being directed toward said bus bar and arrangedsubstantially normal to said insulator, the curved surface of saidarcuately shaped member bearing against said plane surface, and meansfor adjusting said plane surface member toward and away from said busbar to initially secure said insulator in position.

3. In combination, a bus bar, a housing for said bus bar comprising atube of a substantially insulating material, metallic supporting meansfor said bus bar comprising a pair of metallic members constructed to bejoined together to form a. ring; insulators supported on said ring inangular displaced relation about said ring with respect to eachinsulator extending between said ring and bus bar; said supporting meansand insulators positioning said bus bar substantially along the axis ofsaid tube and spaced from the one end to a portion of said ring,

wallthereof; there being a plurality of said rings spaced from eachother, each supporting opposite ends of said tube; additional means oneach ring for supporting an end of said tube; an additional conductivemember on each ring extending closer to said bus bar than the wall ofsaid tube; said tube having a metallic lamination for placing thehousing at ground potential, and an electrically conductive connectionbetween said metallic lamination and said ring.

4. In combination, a bus bar, a housing for said bus bar comprising atube of a substantially insulating material, metallic supporting meansfor said bus bar comprising a pair of metallic members constructed to bejoined together to form a ring; insulators supported on said ring inangular displaced relation about said ring with respect to eachinsulator extending between said ring and bus bar; said supporting meansand insulators positioning said bus bar substantially along the axis ofsaid tube and spaced from the wall thereof; there being a plurality ofsaid rings spaced from each other, each supporting opposite ends of saidtube; additional means on each ring for supporting an end of said tube;said tube having a continuous metallic material embedded therein forplacing the housing at ground potential.

5. In combination, a bus bar, a housing for said bus bar comprising atube of a substantially insulating material, metallic supporting meansfor said bus bar comprising a pair of metallic members constructed to bejoined together to form a ring; insulators supported on said ring inangular displaced relation about said ring with respect to eachinsulator extending between said ring and bus bar; said supporting meansand insulators positioning said bus bar substantially along the axis ofsaid tube and spaced from the wall thereof; there being a plurality ofsaid rings spaced from each other, each supporting opposite ends of saidtube; additional means on each ring for supporting an end of said tube;said tube having an inner and outer metallic lamination for groundingthe bus bar housing and an electrically conductive connection betweensaid tube and said ring.

6. In combination, a bus bar, a bus bar housing comprising an enclosureof insulating material, a supporting ring therefor, said ring includingmeans for supporting said bus bar enclosure,

pivotally mounted insulator means supported on said ring between saidring and said-bus bar for supporting the latter along the axis of saidenclosure; openings in said ring, and means for closing said openings;said last mentioned means comprising a flexible metallic strip securedat the'body of said strip being swingable into engagement with said ringover said openings; and means for releasably securing, the opposite endof said strip to said ring.

7. In combination, a bus bar, a bus bar housing comprising an enclosureof insulation material, a supporting ring; said ring including means forsupporting said busbar enclosure, pivotally mounted insulator meanssupported on said ring between said ring and said bus bar for supportingthe latter along the axis of said enclosure; openings in said ring, andmeans for closing said openings; said last mentioned means comprising aflexible metallic strip entirely surrounding said ring; said strip beingremovable from and replaceable on said ring over said openings; meansfor securing the ends of said strip together to tightly secure the sameon said ring and ventilating holes in a portion of said strip.

8. In combination, a, bus bar, a bus bar housing comprising a continuousintegral tubular bus bar enclosure; a pair of metallic supportingmembers, each forming only a part of a complete ring and being joinedtogether to form a ring and having flanges for supporting saidenclosure, means for supporting said bus bar along the axis of saidenclosure; said last mentioned means comprising a plurality 0f insulatorsupporting members angularly spaced from each other and supported onsaid ring; insulators supported thereby, each of said insulatorsengaging said bus bar and spacing it from the ring, each insulatorhaving a universally pivotal mounting at the end engaging the bus barand an arcuately shaped member at the other end curved on an arc havingthe pivoting point of said universally pivotal mounting as a center;said universally pivotal mounting comprising a. socket member facingsaid bus bar, and a irustrum-conical member secured to said bus bar andpivoted in said socket.

WILLIAM M. SCO'I'I, JR.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 259,235Stieringer June 6, 1882 452,725 Williams May 19, 1891 793,754 Weber July4, 1905 848,047 Procunier -Mar. 26, 1907 898,858 Feldmann et a1 Sept.15, 1908 1,939,552 Hepner et a1 Dec. 12, 1933 1,992,816 De Mask Feb. 26,1935 2,044,580 Leach June 16, 1936 2,064,326 Tietig I Dec. 15, 19362,158,868 Stacy May 16, 1939 2,181,664 Melzer Nov. 28, 1939 2,191,071Duttera Feb. 20, 1940 2,229,006 Rudd Jan, 14, 1941 2,273,135 Ohnesorgeet a1. Feb. 17, 1942 2,275,203 Rudd Mar. 3, 1942 2,293,310 Rudd Aug. 18,1942 2,313,972 Rugg et a1 Mar. 16, 1943 2,335,543 Rudd Nov, 30, 19432,396,131 Scott Mar. 5, 1946 FOREIGN PATEN'I'S Number Country Date GreatBritain 1900

